Evolution of fragment size distributions from the crushing of granular materials

Abstract

We study the fragment size distributions after crushing of single and many particles under uniaxial compression inside a cylindrical container by means of numerical simulations. Under the assumption that breaking goes through the bulk of the particle we obtain the size distributions of fragments for both cases after large displacements. For the single particle crushing, this fragmentation mechanism produces a log-normal size distribution, which deviates from the power-law distribution of fragment sizes for the packed bed. We show that as the breaking process evolves, a power-law dependency on the displacement is present for the single grain, while for the many grains system, the distribution converges to a steady state. We further investigate the force networks and the average coordination number as a function of the particle size, which gives inside about the origin of the power-law distributions for the granular assembly under uniaxial compression.

Behavior of confined granular beds under cyclic thermal loading

“…Following Refs. [11,12], we impose disorder and asymmetry by placing vertices randomly on the surface of an ellipsoid with normalized axes a e = 1, b e = 0.95, and c e = 0.9.…”

Critical Scaling of Solid Fragmentation at Quasistatic and Finite Strain Rates

“…Intriguingly, it is often observed in fragmented granular matter that N (M ) decays as a power of increasing M with an exponent τ , N (M ) ∼ M −τ [21]. This has been seen in experiments and simulations of impacted [22][23][24][25], crushed [26][27][28][29], and sheared [1,30] solids. Fragmentation has therefore been postulated to be an instance of self-organized criticality [13,22,31], a theory that some systems can naturally evolve towards a critical state [32].…”

“…In ballistic impacts, τ depended on the initial geometry [22]. In simulations, τ may depend on plasticity [25], the extent of loading [29], and the rules of fracture [49]. Lattice models suggested fragility may affect τ [21].…”

Microstructural origins of crushing strength for inherently anisotropic brittle materials

“…Numerical approaches have proven successful at analyzing these materials because they are able to reproduce complex failure mechanisms under controlled geometries. Some of these approaches use, for example, finite-elements (Sulem and Cerrolaza, 2002;Amir Reza Beyabanaki et al, 2009), discrete-element methods with bonded bodies (Potyondy and Cundall, 2004;Cho et al, 2007;Lan et al, 2010;Scholtès and Donzé, 2013;Kazerani, 2013;Gao and Stead, 2014), splitting or replacing mechanisms (Cantor et al, 2015;Ciantia et al, 2015;Gladkyy and Kuna, 2017;Iliev et al, 2019), or coupled discrete-finite element strategies (Mahabadi et al, 2010;Bagherzadeh Kh. et al, 2011;Guo and Zhao, 2014;Ma et al, 2014).…”